Fitting for a cask having an overpressure function

A fitting arrangement for a cask, comprising:

• a fitting sleeve with a riser pipe arranged therein and resiliently moveable relative thereto,
• wherein the fitting sleeve has a conically extending inner sealing surface tapering toward an upper end,
• a seal incorporated between the inner sealing surface and an upper end of the riser pipe,
• a spring member pressing the riser pipe with the seal against the sealing surface,
• the seal is arranged internally in the upper end of the riser pipe, wherein a sealing body is arranged in the upper end of the riser pipe and is resiliently movable relative thereto,
• the sealing body comes to bear with form-fit engagement on an internal sealing surface of the seal on account of a spring force,
• the seal has an inner reinforcement ring which is surrounded by an elastic sealing material, and the reinforcement ring has a material recess on its outer jacket surface such that the distance from the reinforcement ring to the inner sealing surface of the fitting sleeve is increased,
• wherein the material recess is designed as a beveled surface, or in that the material recess is designed as a groove with an at least partially beveled surface, and in that the beveled surface has a flat profile, or in that the beveled surface has a curved profile, in such a way that, in the event of an overpressure, a part of the elastic sealing material is reversibly deformed elastically outward in the region of the material recess and the part can be returned to its initial position after the overpressure function is triggered.